Abstract: A laterally diffused metal oxide semiconductor (LDMOS) device, and a method of manufacturing the same are provided. The LDMOS device can include a drain region of a bootstrap field effect transistor (FET), a source region of the bootstrap FET, a drift region formed between the drain region and the source region, and a gate formed at one side of the source region and on the drift region.

Abstract: An electronic device can include a semiconductor layer having a primary surface, and a Schottky contact comprising a metal-containing member in contact with a horizontally-oriented lightly doped region within the semiconductor layer and lying adjacent to the primary surface. In an embodiment, the metal-containing member lies within a recess in the semiconductor layer and contacts the horizontally-oriented lightly doped region along a sidewall of the recess. In other embodiment, the Schottky contact may not be formed within a recess, and a doped region may be formed within the semiconductor layer under the horizontally-oriented lightly doped region and have a conductivity type opposite the horizontally-oriented lightly doped region. The Schottky contacts can be used in conjunction with power transistors in a switching circuit, such as a high-frequency voltage regulator.

Abstract: A power semiconductor device is provided, which can prevent an electric field from concentrating on a diode region, and can improve a breakdown voltage by creating an impurity concentration gradient in the diode region to increase from a termination region to an active cell region to cause reverse current to be distributed to the active cell region.

Abstract: A semiconductor device includes a semiconductor body and a source metallization arranged on a first surface of the body. The body includes: a first semiconductor layer including a compensation-structure; a second semiconductor layer adjoining the first layer, comprised of semiconductor material of a first conductivity type and having a doping charge per horizontal area lower than a breakdown charge per area of the semiconductor material; a third semiconductor layer of the first conductivity type adjoining the second layer and comprising at least one of a self-charging charge trap, a floating field plate and a semiconductor region of a second conductivity type forming a pn-junction with the third layer; and a fourth semiconductor layer of the first conductivity type adjoining the third layer and having a maximum doping concentration higher than that of the third layer. The first semiconductor layer is arranged between the first surface and the second semiconductor layer.

Abstract: High-mobility vertical trench DMOSFETs and methods for manufacturing are disclosed. A source region, a drain region or a channel region of a high-mobility vertical trench DMOSFET may comprise silicon germanium (SiGe) that increases the mobility of the charge carriers in the channel region. In some embodiments the channel region may be strained to increase channel charge carriers mobility.

Abstract: In one general aspect, a method of forming a field effect transistor can include forming a well region in a semiconductor region of a first conductivity type where the well region is of a second conductivity type and has an upper surface and a lower surface. The method can include forming a gate trench extending into the semiconductor region to a depth below a depth of the lower surface of the well region, and forming a stripe trench extending through the well region and into the semiconductor region to a depth below the depth of the gate trench. The method can also include forming a contiguous source region of the first conductivity type in the well region where the source region being in contact with the gate trench and in contact with the stripe trench.

Abstract: A semiconductor device includes a semiconductor body including a first surface. The semiconductor device further includes a continuous silicate glass structure over the first surface. A first part of the continuous glass structure over an active area of the semiconductor body includes a first composition of dopants that differs from a second composition of dopants in a second part of the continuous glass structure over an area of the semiconductor body outside of the active area.

Abstract: A method for manufacturing a semiconductor power device on a semiconductor substrate supporting a drift region composed of an epitaxial layer by growing a first epitaxial layer followed by forming a first hard mask layer on top of the epitaxial layer; applying a first implant mask to open a plurality of implant windows and applying a second implant mask for blocking some of the implant windows to implant a plurality of dopant regions of alternating conductivity types adjacent to each other in the first epitaxial layer; repeating the first step and the second step by applying the same first and second implant masks to form a plurality of epitaxial layers then carrying out a device manufacturing process on a top side of the epitaxial layer with a diffusion process to merge the dopant regions of the alternating conductivity types as doped columns in the epitaxial layers.

Abstract: A method for manufacturing a semiconductor device includes irradiating light to an effective region of a semiconductor substrate. A wavelength of the light is a wavelength adapted so that light absorptance of the semiconductor substrate increases if an intensity of the light increases. The light is irradiated so that a focus point of the light is made within the semiconductor substrate in the irradiating.

Abstract: A transistor structure that improves ESD withstand voltages is offered. A high impurity concentration drain layer is formed in a surface of an intermediate impurity concentration drain layer at a location separated from a drain-side end of a gate electrode. And a P-type impurity layer is formed in a surface of a substrate between the gate electrode and the high impurity concentration drain layer so as to surround the high impurity concentration drain layer. When a parasitic bipolar transistor is turned on by an abnormal surge, electrons travel from a source electrode to a drain electrode. Here, electrons travel dispersed in the manner to avoid a vicinity X of the surface of the substrate and travel through a deeper path to the drain electrode as indicated by arrows in FIG. 4.

Abstract: A semiconductor device includes a base layer, a second conductivity type semiconductor layer, a first insulating film, and a first electrode. The first insulating film is provided on an inner wall of a plurality of first trenches extending from a surface of the second conductivity type semiconductor layer toward the base layer side, but not reaching the base layer. The first electrode is provided in the first trench via the first insulating film, and provided in contact with a surface of the second conductivity type semiconductor layer. The second conductivity type semiconductor layer includes first and second regions. The first region is provided between the first trenches. The second region is provided between the first second conductivity type region and the base layer, and between a bottom part of the first trench and the base layer. The second region has less second conductivity type impurities than the first region.

Abstract: A LDMOS transistor is implemented in a first impurity region on a substrate. The LDMOS transistor has a source that includes a second impurity region. The second impurity region is implanted into the surface of the substrate within the first impurity region. Additionally, the LDMOS transistor has a drain that includes a third impurity region. The third impurity region is implanted into the surface of the substrate within the first impurity region. The third impurity region is spaced a predetermined distance away from a gate of the LDMOS transistor. The drain of the LDMOS transistor further includes a fourth impurity region within the third impurity region. The fourth impurity region provides an ohmic contact for the drain.

Abstract: A semiconductor device is provided. The semiconductor device includes a gate on a substrate, a source region at a first side of the gate, a first conductive type body region under the source region, a second conductive type drain region at a second side of the gate, a device isolation region in the substrate between the source region and the drain region and overlapping part of the gate, and a first buried layer extending in a direction from the source region to the drain region, the first buried layer under the body region, overlapping part of the device isolation region, and not overlapping the drain region.

Abstract: It is intended to provide a semiconductor device capable to improve a controllability of dv/dt by a gate drive circuit during a turn-on switching period, while maintaining a low loss and a high breakdown voltage. Trench gates are disposed so as to have narrow distance regions and wide distance regions, wherein each of the narrow distance regions is provided with a channel region, and each of the wide distance regions is provided with trenches, each trench having an electrode electrically connected to the emitter electrode. In this manner, even if a floating-p layer is removed, it is possible to reduce a feedback capacity and maintain a breakdown voltage.

Abstract: The present invention discloses a high voltage device and a manufacturing method thereof. The high voltage device includes: a first conductive type substrate in which isolation regions are formed for defining a device region; a gate formed on the first conductive type substrate; a source and a drain formed in the device region and located at both sides of the gate respectively, and doped with second conductive type impurities; a second conductive type well, which is formed in the first conductive type substrate, and surrounds the drain from top view; and a first deep trench isolation structure, which is formed in the first conductive type substrate, and is located in the second conductive type well between the source and the drain from top view, wherein the depth of the first deep trench isolation structure is deeper than the second conductive type well from the cross-sectional view.

Abstract: According to one embodiment, a semiconductor device includes a base region of a second conductivity type, a drift region of a first conductivity type, an insulating layer, a drain region of the first conductivity type, a gate oxide film, a gate electrode, a first main electrode, and a second main electrode. The base region includes a source region of the first conductivity type. The drift region is adjacent to the base region. The insulating layer is provided from a surface to inside of the drift region. The drain region is provided in the surface of the drift region and opposed to the source region across the base region and the insulating layer. The gate oxide film is provided on a surface of the base region. The gate electrode is provided on the gate oxide film. The first main electrode is connected to the source region. The second main electrode is connected to the drain region.

Abstract: A semiconductor device includes a source metallization, a source region of a first conductivity type in contact with the source metallization, a body region of a second conductivity type which is adjacent to the source region. The semiconductor device further includes a first field-effect structure including a first insulated gate electrode and a second field-effect structure including a second insulated gate electrode which is electrically connected to the source metallization. The capacitance per unit area between the second insulated gate electrode and the body region is larger than the capacitance per unit area between the first insulated gate electrode and the body region.

Abstract: The silicon carbide semiconductor device includes a substrate, a drift layer, a base region, a source region, a trench, a gate insulating layer, a gate electrode, a source electrode, a drain electrode, and a deep layer. The deep layer is disposed under the base region and is located to a depth deeper than the trench. The deep layer is divided into a plurality of portions in a direction that crosses a longitudinal direction of the trench. The portions include a group of portions disposed at positions corresponding to the trench and arranged at equal intervals in the longitudinal direction of the trench. The group of portions surrounds corners of a bottom of the trench.

Abstract: In a semiconductor device in which an IGBT, a control circuit for the IGBT and so on are formed on an SOI substrate divided by trenches, the invention is directed to providing the IGBT with a higher breakdown voltage, an enhanced turn-off characteristic and so on. An N type epitaxial layer is formed on a dummy semiconductor substrate, a trench is formed in the N type epitaxial layer, an N type buffer layer and then a P type embedded collector layer are formed on the sidewall of the trench and the front surface of the N type epitaxial layer, and the bottom of the trench and the P+ type embedded collector layer are covered by an embedded insulation film. The embedded insulation film is covered by a polysilicon film, and a P type semiconductor substrate is attached to the polysilicon film with an insulation film being interposed therebetween.

Abstract: A bipolar semiconductor device and manufacturing method. One embodiment provides a diode structure including a structured emitter coupled to a first metallization is provided. The structured emitter includes a first weakly doped semiconductor region of a first conductivity type which forms a pn-load junction with a weakly doped second semiconductor region of the diode structure. The structured emitter includes at least a highly doped first semiconductor island of the first conductivity type which at least partially surrounds a highly doped second semiconductor island of the second conductivity type.

Abstract: In an embodiment, an apparatus includes a source region, a gate region and a drain region supported by a substrate, and a drift region including a plurality of vertically extending n-wells and p-wells to couple the gate region and the drain region of a transistor, wherein the plurality of n-wells and p-wells are formed in alternating longitudinal rows to form a superjunction drift region longitudinally extending between the gate region and the drain region of the transistor.

Abstract: A high voltage metal-oxide-semiconductor laterally diffused device (HV LDMOS), particularly an insulated gate bipolar junction transistor (IGBT), and a method of making it are provided in this disclosure. The device includes a semiconductor substrate, a gate structure formed on the substrate, a source and a drain formed in the substrate on either side of the gate structure, a first doped well formed in the substrate, and a second doped well formed in the first well. The gate, source, second doped well, a portion of the first well, and a portion of the drain structure are surrounded by a deep trench isolation feature and an implanted oxygen layer in the silicon substrate.

Abstract: It is desirable to reduce chip area, lower on resistance and improve electric current driving capacity of a DMOS transistor in a semiconductor device with a DMOS transistor. On the surface of an N type epitaxial layer, a P+W layer of the opposite conductivity type (P type) is disposed and a DMOS transistor is formed in the P+W layer. The epitaxial layer and a drain region are insulated by the P+W layer. Therefore, it is possible to form both the DMOS transistor and other device element in a single confined region surrounded by an isolation layer. An N type FN layer is disposed on the surface region of the P+W layer beneath the gate electrode. An N+D layer, which is adjacent to the edge of the gate electrode of the drain layer side, is also formed. P type impurity layers (a P+D layer and a FP layer), which are located below the drain layer, are disposed beneath the contact region of the drain layer.

Abstract: A transistor structure that improves an ESD withstand voltage is offered. There is formed a P-type insulating isolation layer that divides an N-type epitaxial layer into a plurality of regions and isolates neighboring regions from each other. A diffusion layer doped with high concentration N-type impurities and an electrode extraction layer are formed in a surface of the epitaxial layer between a low impurity concentration drain layer and the insulating isolation layer. The diffusion layer and the electrode extraction layer are connected with a drain electrode. When an excessive positive surge voltage is applied to a source electrode, a parasitic diode that makes a current path including the diffusion layer and the electrode extraction layer is turned on to shunt an ESD current from the source electrode to the drain electrode, in addition to other parasitic diodes included in a conventional structure.

Abstract: A semiconductor device includes a semiconductor layer of a first conductivity type and a semiconductor layer of a second conductivity type formed thereon. The semiconductor layer of the second conductivity type is characterized by a first thickness. The semiconductor device includes a set of trenches having a predetermined depth and extending into the semiconductor layer of the second conductivity type, thereby defining interfacial regions disposed between the semiconductor layer of the second conductivity type and each of the trenches. The trenches comprises a distal portion consisting essentially of a dielectric material disposed therein and a proximal portion comprising the dielectric material and a gate material disposed interior to the dielectric material in the proximal portion of the trench. The semiconductor device further includes a source region coupled to the semiconductor layer of the second conductivity type.

Abstract: A body layer of a first conductivity type is formed on a semiconductor substrate, and a source layer of a second conductivity type is formed in a surface region of the body layer. An offset layer of the second conductivity type is formed on the semiconductor substrate, and a drain layer of the second conductivity type is formed in a surface region of the offset layer. An insulating film is embedded in a trench formed in the surface region of the offset layer between the source layer and the drain layer. A gate insulating film is formed on the body layer and the offset layer between the source layer and the insulating film. A gate electrode is formed on the gate insulating film. A first peak of an impurity concentration profile in the offset layer is formed at a position deeper than the insulating film.

Abstract: A silicon carbide power MOSFET having a drain region of a first conductivity type, a base region of a second conductivity type above the drain region, and a source region of the first conductivity type adjacent an upper surface of the base region, the base region including a channel extending from the source region through the base region adjacent a gate interface surface thereof, the channel having a length less than approximately 0.6 ?m, and the base region having a doping concentration of the second conductivity type sufficiently high that the potential barrier at the source end of the channel is not lowered by the voltage applied to the drain. The MOSFET includes self-aligned base and source regions as well as self-aligned ohmic contacts to the base and source regions.

Abstract: A method of manufacturing an SiC semiconductor device according to the present invention includes the steps of (a) by using a single mask, etching regions of an SiC semiconductor layer which serve as an impurities implantation region and a mark region, to form recesses, (b) by using the same mask as in the step (a), performing ion-implantation in the recesses of the regions which serve as the impurities implantation region and the mark region, at least from an oblique direction relative to a surface of the SiC semiconductor layer and (c) positioning another mask based on the recess of the region which serves as the impurities implantation region or the mark region, and performing well implantation in a region containing the impurities implantation region.

Abstract: A sinker layer is in contact with a first conductivity-type well and a second conductivity-type drift layer, respectively, and is separated from a first conductivity-type collector layer. A second conductivity-type diffusion layer (second second-conductivity-type high-concentration diffusion layer) is formed in the surface layer of the sinker layer. The second conductivity-type diffusion layer has a higher impurity concentration than that of the sinker layer. The second conductivity-type diffusion layer and the first conductivity-type collector layer are isolated from each other with an element isolation insulating film interposed therebetween.

Abstract: A controlled-punch-through semiconductor device with a four-layer structure is disclosed which includes layers of different conductivity types, a collector on a collector side, and an emitter on an emitter side which lies opposite the collector side. The semiconductor device can be produced by a method performed in the following order: producing layers on the emitter side of wafer of a first conductivity type; thinning the wafer on a second side; applying particles of the first conductivity type to the wafer on the collector side for forming a first buffer layer having a first peak doping concentration in a first depth, which is higher than doping of the wafer; applying particles of a second conductivity type to the wafer on the second side for forming a collector layer on the collector side; and forming a collector metallization on the second side.

Abstract: A reverse-conducting insulated gate bipolar transistor includes a wafer of first conductivity type with a second layer of a second conductivity type and a third layer of the first conductivity type. A fifth electrically insulating layer partially covers these layers. An electrically conductive fourth layer is electrically insulated from the wafer by the fifth layer. The third through the fifth layers form a first opening above the second layer. A sixth layer of the second conductivity type and a seventh layer of the first conductivity type are arranged alternately in a plane on a second side of the wafer. A ninth layer is formed by implantation of ions through the first opening using the fourth and fifth layers as a first mask.

Abstract: A horizontal semiconductor device includes a semiconductor substrate of a first conductivity type and a semiconductor region of a second conductivity type on the semiconductor substrate. The device includes a collector layer of the first conductivity type within the semiconductor region, an endless base layer of the first conductivity type within the semiconductor region, and an endless first emitter layer of the second conductivity type in the endless base layer. The endless base layer is off the collector layer but surrounds the collector layer. A movement of carriers between the endless first emitter layer and the collector layer is controlled in a channel region formed in the endless base layer. An insulation film is disposed between the semiconductor substrate and the semiconductor region. A region of the first conductivity type is disposed in the semiconductor region to contact with a surface of the endless base layer nearest the semiconductor substrate.

Abstract: A method of manufacturing a SOI high voltage power chip with trenches is disclosed. The method comprises: forming a cave and trenches at a SOI substrate; filling oxide in the cave; oxidizing the trenches, forming oxide isolation regions for separating low voltage devices at the same time; filling oxide in the oxidized trenches; and then forming drain regions, source regions and gate regions for a high voltage power device and low voltage devices. The process involves depositing an oxide layer overlapping the cave of the SOI substrate. A SOI high voltage power chip thus made will withstand at least above 700V voltage.

Abstract: A LDMOS transistor is implemented in a first impurity region on a substrate. The LDMOS transistor has a source that includes a second impurity region. The second impurity region is implanted into the surface of the substrate within the first impurity region. Additionally, the LDMOS transistor has a drain that includes a third impurity region. The third impurity region is implanted into the surface of the substrate within the first impurity region. The third impurity region is spaced a predetermined distance away from a gate of the LDMOS transistor. The drain of the LDMOS transistor further includes a fourth impurity region within the third impurity region. The fourth impurity region provides an ohmic contact for the drain.

Abstract: A semiconductor device includes a diode formed by making use of a DMOS transistor structure. In addition to such a DMOS transistor structure, the semiconductor device includes a second buried layer of the first conductivity type being provided on a first buried layer of a second conductivity type that is in a floating state. Moreover, the second buried layer of the first conductivity type and a second diffusion region of the first conductive type are connected by a first diffusion region of the first conductivity type. A first electrode is set as anode, and a second electrode and a third electrode are short-circuited and set as cathode.

Abstract: A semiconductor device includes: a semiconductor substrate; an IGBT element including a collector region; a FWD element including a cathode region adjacent to the collector region; a base layer on the substrate; multiple trench gate structures including a gate electrode. The base layer is divided by the trench gate structures into multiple first and second regions. Each first region includes an emitter region contacting the gate electrode. Each first region together with the emitter region is electrically coupled with an emitter electrode. The first regions include collector side and cathode side first regions, and the second regions include collector side and cathode side second regions. At least a part of the cathode side second region is electrically coupled with the emitter electrode, and at least a part of the collector side second region has a floating potential.

Abstract: An electronic device can include a first layer having a primary surface, a well region lying adjacent to the primary surface, and a buried doped region spaced apart from the primary surface and the well region. The electronic device can also include a trench extending towards the buried doped region, wherein the trench has a sidewall, and a sidewall doped region along the sidewall of the trench, wherein the sidewall doped region extends to a depth deeper than the well region. The first layer and the buried region have a first conductivity type, and the well region has a second conductivity type opposite that of the first conductivity type. The electronic device can include a conductive structure within the trench, wherein the conductive structure is electrically connected to the buried doped region and is electrically insulated from the sidewall doped region. Processes for forming the electronic device are also described.

Abstract: An LDMOSFET transistor (100) is provided which includes a substrate (101), an epitaxial drift region (104) in which a drain region (116) is formed, a first well region (107) in which a source region (112) is formed, a gate electrode (120) formed adjacent to the source region (112) to define a first channel region (14), and a grounded substrate injection suppression guard structure that includes a patterned buried layer (102) in ohmic contact with an isolation well region (103) formed in a predetermined upper region of the substrate so as to be spaced apart from the first well region (107) and from the drain region (116), where the buried layer (102) is disposed below the first well region (107) but not below the drain region (116).

Abstract: A vertically-conducting planar-gate field effect transistor includes a silicon region of a first conductivity type, a silicon-germanium layer extending over the silicon region, a gate electrode laterally extending over but being insulated from the silicon-germanium layer, a body region of the second conductivity type extending in the silicon-germanium layer and the silicon region, and source region of the first conductivity type extending in the silicon-germanium layer. The gate electrode laterally overlaps both the source and body regions such that a portion of the silicon germanium layer extending directly under the gate electrode between the source region and an outer boundary of the body region forms a channel region.

Abstract: A plurality of cell structures of a vertical power device are formed at a semiconductor substrate. One cell structure included in the plurality of cell structures and located in a central portion CR of the main surface has a lower current carrying ability than the other cell structure included in the plurality of cell structures and located in an outer peripheral portion PR of the main surface. This provides a power semiconductor device having a long power cycle life.

Abstract: A plurality of cell structures of a vertical power device are formed at a semiconductor substrate. One cell structure included in the plurality of cell structures and located in a central portion CR of the main surface has a lower current carrying ability than the other cell structure included in the plurality of cell structures and located in an outer peripheral portion PR of the main surface. This provides a power semiconductor device having a long power cycle life.

Abstract: A trench-gate transistor has an integral first layer of silicon dioxide extending from the upper surface of the semiconductor body over top corners of each cell array trench. The integral first layer also provides a thin gate dielectric insulating layer for a thick gate electrode and the integral first layer also provides a first part of a stack of materials which constitute a thick trench sidewall insulating layer for a thin field plate. Consistent with an example embodiment, there is a method of manufacture. A hardmask used to etch the trenches is removed before providing the silicon dioxide layer. The layer is then protected by successive selective etching of the oxide layer and the nitride layer in the upper parts of the trenches. After the gate electrodes are provided, layers for the channel accommodating regions and source regions may be formed through the oxide layer on the upper surface.

Abstract: Disclosed is a semiconductor device wherein the switching speed of a transistor is increased. Specifically disclosed is a semiconductor device comprising a semiconductor layer formed on a part of an insulating layer, a first transistor formed on a lateral face of the semiconductor layer and having a first gate insulating film, a first gate electrode and two first impurity layers forming a source and a drain, and a second transistor formed on another lateral face of the semiconductor layer and having a second gate insulating film, a second gate electrode and two second impurity layers forming a source and a drain.

Abstract: A structure and method of fabricating the structure. The structure including: a dielectric isolation in a semiconductor substrate, the dielectric isolation extending in a direction perpendicular to a top surface of the substrate into the substrate a first distance, the dielectric isolation surrounding a first region and a second region of the substrate, a top surface of the dielectric isolation coplanar with the top surface of the substrate; a dielectric region in the second region of the substrate; the dielectric region extending in the perpendicular direction into the substrate a second distance, the first distance greater than the second distance; and a first device in the first region and a second device in the second region, the first device different from the second device, the dielectric region isolating a first element of the second device from a second element of the second device.

Abstract: A semiconductor wafer having IGBT elements and transistors formed on a surface thereof is prepared. Electron beams are emitted all over the surface of the semiconductor wafer. Recombination centers are formed in the IGBT elements and the transistors. ON voltages of the transistors are measured by a measurement device, and lifetimes defined in the IGBT elements and the transistors are recovered by a prescribed annealing treatment. When the lifetimes are recovered, a control device controls an annealing treatment amount in the annealing treatment based on the measured ON voltages of the transistors such that ON voltages of the IGBT elements are each equal to a desired ON voltage. Variations in the ON voltages of a plurality of IGBT elements obtained from the semiconductor wafer are reduced.

Abstract: An integrated structure of an IGBT and a diode includes a plurality of doped cathode regions, and a method of forming the same is provided. The doped cathode regions are stacked in a semiconductor substrate, overlapping and contacting with each other. As compared with other doped cathode regions, the higher a doped cathode region is disposed, the larger implantation area the doped cathode region has. The doped cathode regions and the semiconductor substrate have different conductive types, and are applied as a cathode of the diode and a collector of the IGBT. The stacked doped cathode regions can increase the thinness of the cathode, and prevent the wafer from being overly thinned and broken.

Abstract: A plurality of cell structures of a vertical power device are formed at a semiconductor substrate. One cell structure included in the plurality of cell structures and located in a central portion CR of the main surface has a lower current carrying ability than the other cell structure included in the plurality of cell structures and located in an outer peripheral portion PR of the main surface. This provides a power semiconductor device having a long power cycle life.

Abstract: An improved insulated gate field effect device (60) is obtained by providing a substrate (20) desirably comprising a III-V semiconductor, having a further semiconductor layer (22) on the substrate (20) adapted to contain the channel (230) of the device (60) between spaced apart source-drain electrodes (421, 422) formed on the semiconductor layer (22). A dielectric layer (24) is formed on the semiconductor layer (22). A sealing layer (28) is formed on the dielectric layer (24) and exposed to an oxygen plasma (36). A gate electrode (482) is formed on the dielectric layer (24) between the source-drain electrodes (421, 422). The dielectric layer (24) preferably comprises gallium-oxide (25) and/or gadolinium-gallium oxide (26, 27), and the oxygen plasma (36) is preferably an inductively coupled plasma. A further sealing layer (44) of, for example, silicon nitride is desirably provided above the sealing layer (28).

Abstract: A silicon carbide semiconductor device includes: a semiconductor substrate having a silicon carbide substrate, a first semiconductor layer, a second semiconductor layer, and a third semiconductor layer; a trench penetrating the second and the third semiconductor layers to reach the first semiconductor layer; a channel layer on a sidewall and a bottom of the trench; an oxide film on the channel layer; a gate electrode on the oxide film; a first electrode connecting to the third semiconductor layer; and a second electrode connecting to the silicon carbide substrate. A position of a boundary between the first semiconductor layer and the second semiconductor layer is disposed lower than an utmost lowest position of the oxide film.

Abstract: A trench type IGBT as disclosed herein includes a plurality of channel regions having one threshold voltage for the normal operation of the device and a plurality of channel regions having a threshold voltage higher than the threshold voltage for the normal operation of the device.